1. Field of the Invention
The present invention relates to ureteral stents, and more particularly relates to an improved stent for placement in a patient's ureter wherein the stent body is of a stiffer material to promote smooth advancement, and the bladder coil is of a softer material that reduces irritation at the trigone, and a collar interfaces the stent body and bladder coil, the collar having an annular shoulder that accepts a pusher tube above the bladder coil.
2. General Background
Common problems encountered during ureteral stenting include stent buckling during placement, antegrade and retrograde migration, and patient discomfort. Some stents use J-shaped end portions that register in the renal pelvis and bladder respectively. The J-shaped ends can straighten at the top or proximate end portion of the stent so that the entire stent migrates in the ureter.
Most stents are of a singular material. This requires a stent of stiff enough material so that the stent can be installed with a pusher without risk of buckling. However, this stiff stent material can irritate bladder tissue.